Classification Types

When you classify feature data, classification method
and the number of classes you specify greatly affects how a theme is
displayed and interpreted.
In the examples below, notice how the theme's display changes when the
Pop_93 field values are grouped into five classes using different classification
methods. The features have been grouped with the Natural Breaks, Equal
Area (the area they occupy), Standard Deviation, Equal Interval (the
interval between classes), and the Quantile (quantity of features in
each class) classification methods.